Illinois Attorney General Lisa Madigan is warning Chicago-based CareerBuilder and five other national job-search companies that some of their online search functions exclude older workers and could violate age discrimination laws.

Madigan sent letters to Indeed, Beyond.com, Ladders, Monster Worldwide and Vault as well as CareerBuilder requesting information about functions that appear to keep older people from building accurate resumes or profiles, according to a news release from her office.

For example, one site had a drop-down menu that offered 1980 as the earliest possible start date for education or previous employment. Other sites used dates ranging from 1950 to 1970 as cut-offs.

"Today's workforce includes many people working in their 70's and 80's," Madigan said in the release. "Barring older people from commonly used job-search sites because of their age is discriminatory and negatively impacts our economy."

The attorney general's Civil Rights Bureau, which enforces state and federal civil rights laws, is examining the practices. Excluding older workers could violate the Illinois Human Rights Act and the federal Age Discrimination in Employment Act.

In an email, CareerBuilder spokeswoman Jennifer Sullivan Grasz said the company "is committed to helping workers of all ages find job opportunities, and is fixing this unfortunate oversight."

Ladders, based in New York, said Thursday that it has not yet received a letter from Madigan and that it does not participate in the alleged practices.

The online job search service, which caters to professionals, does not restrict dates on resumes people submit and, in order to combat age discrimination, does not ask users for a college graduation year, Stephanie Chan, vice president of marketing, said in an emailed statement. An optional work experience section limits experience to the past 50 years.

"We have spoken publicly about this topic and feel very passionate about combating age discrimination in the workforce," Chan said. "What we have shared with job seekers is our belief that to effectively market yourself it is best not to discuss work experience from more than 20 years ago."

Beyond, based in King of Prussia, Pa., said it will be happy to respond to Madigan once it receives the letter.

"Discrimination has no part in the hiring process and that's why we take such care to help job seekers (and hiring managers) carefully consider all information they put forth during the job search process to avoid any conscious or unconscious bias," the company said in an emailed statement.

Monster, Indeed and Vault did not immediately respond to requests for comment.